class Circle implements ShapeArea{
private double r;
public Circle(double r){
this.r = r;
}
public double getArea() {
return Math.PI * r * r;
}
public double getPerimeter() {
return 3 * Math.PI * r;
}
public String toString(){
return "r =" + r + ", area = " + getArea() + ", perimeter = " + getPerimeter();
}
}
